


Age is just a number...

by cthchewy



Series: Keyhole 'verse [2]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Age Difference, Alternate Universe - Modern Setting, Crack Treated Seriously, F/M, Family Feels, Urban Fantasy
Language: English
Status: Completed
Published: 2020-03-10
Updated: 2020-03-26
Packaged: 2021-03-01 05:01:10
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,764
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23089780
Author URL: https://archiveofourown.org/users/cthchewy/pseuds/cthchewy
Summary: Jeralt suffers.
Relationships: Jeralt Reus Eisner/Leonie Pinelli, My Unit | Byleth/Seteth
Series: Keyhole 'verse [2]
Series URL: https://archiveofourown.org/series/1645483
Comments: 28
Kudos: 106





	1. ...until your daughter brings home the wrong sort of "millennial"

The last text on his phone says, “Love you, see you soon.”

Jeralt’s weariness from what seems like the whole year catches up to him at that moment and he heaves an epic long sigh that deflates his entire being and rattles him down to his bones. He can’t hold anything against the kid after she says something like that, even if the rest of the conversation before it was about her… boyfriend. Just the thought of it makes Jeralt grit his teeth.

Byleth had always been different, growing up. She almost never cried as a child, and would instead stare expressionlessly until _other_ children started crying and running scared from her. She didn’t even say her first word until she was almost six and about to start primary school. The kindergarten teacher had called a meeting with social workers and special needs educators, and they’d somehow gotten into a heated argument on how Jeralt was going to raise her by himself when his military career took him on the move across the country and sometimes internationally, uprooting every couple of years.

They said she’d never catch up that way, without a stable home environment. It wasn’t his proudest moment, but he lost his temper then, perhaps fearing – panicking – that his incompetence would get his daughter taken away. He hadn’t made it so far up the chain of command by not knowing what to do, but every day he spent as Byleth’s dad had given him that uncomfortable feeling. So he lashed out, cursed and yelled that he’d raise her however he damn well pleased, that they’d take her over his dead body.

...And he definitely made things worse. But it was then that Byleth first spoke. It was then that she first cried.

With tears streaming unnoticed down her chubby cheeks, she said, “I wanna stay with daddy.” And then, after they all got over the shock and bombarded her with questions, she said, “I can talk. Don’t like to,” and wandered off to play with her puzzles, content that by having heard her speak they would allow her to start school as planned. If Byleth was extra clingy to him for the next week or so, it was in such small ways that no one outside of their little family would ever notice.

Byleth has come a long way since then. She talks freely now – not a lot, but enough. (Jeralt isn’t much of a talker either.) She’ll never be considered skilled when it comes to social interactions, but she functions. Despite Jeralt’s fuck ups she’s turned out to be a strong independent woman, smart as a whip, tough as nails, all of that cliche stuff.

She just hasn’t _dated_ before, aside from that one disaster when her high school prom date wouldn’t take no for an answer and ended up with her fist in his face. “Girls are supposed to slap!” he tried to say around a mouthful of blood, three and a half teeth lying in a puddle by his feet. Jeralt was so proud that night, when she told him the story at the police station…

 _Besides_ that, she hasn’t dated. Probably. Unless she just hasn’t told her old man, because it sure seems like this relationship she’s in got pretty darn serious before he was clued in. He scrolls back up on his phone to re-read the previous messages. They’re coming over to visit soon, so he’ll try his best to be prepared.

The boyfriend’s name is Seteth. They met at work. Okay, fine. There are tons of people working at the university, so that really says nothing. It could be a fellow instructor, a librarian, a security guard, a tech guy. Hell, it could be a line cook in a dining hall. It could be anything at all.

Most of the other texts are Byleth trying to reassure him that everything is fine, they’ll totally get along. She thinks they'll grunt and be dour-faced at each other, go fishing maybe. This description briefly worries Jeralt who, while he takes pride in Byleth being a daddy’s girl (not like she had a choice), he doesn’t want her to actually have weird sexual hang-ups and bring home a clone of him.

The guy likes fishing, though. He can’t be all that bad if he likes fishing.

Fishing is love in the Eisner family. On this point at least, Jeralt taught his daughter well.

* * *

Seteth is out there in the living room, nursing a beer, trying not to fidget. Jeralt has just dragged Byleth into the kitchen under the pretense of helping him get the dinner table set up.

“Am I supposed to be okay with this? I’m not okay with this,” he says.

In the worst case scenario, he’d been prepared for her to bring home the stereotypical millennial, some man-child with his hair up in a bun and a militant vegan agenda on the tip of his tongue. The fishing would turn out to only be catch and release, and he’d wear lumberjack chic without ever having gone camping in his life. Jeralt has practiced being okay with that.

He has not practiced being okay with _this_. Seteth is very well put together, serious and focused, has old-fashioned manners, and obviously respects Byleth. That’s good, that’s everything he could have wanted, which meant it was too good to be true.

The problem is there’s an age gap, and clearly not a small one despite his youthful looks, by the mention of him being a widower single father with a _daughter in high school_. High school!

“I don’t understand,” Byleth says, reaching into the cupboard for plates. “What part are you not okay with?”

“He’s a father already.”

Shrug. “So are you, and I’ve never complained about you dating younger women. Don’t be a hypocrite, dad.”

“I’m _not_.” Jeralt gives into the urge to put a hand on his face. “Look, he’s got what, ten, fifteen years on you? A difference that big _matters_ when you’re young. Don’t you think it’s strange to be closer in age to his _daughter_ than to him?”

Byleth shrugs again. “Mom was that much older than you.”

“Oh come on, kid! Your mother was a quarter Nabatean, you know they don’t age the same… Oh no. NO.”

Byleth nods. “Seteth is Nabatean too.”

Fuck no. They’re dragon fuckers. The Eisner family is dragon fuckers. Instead of worrying that Byleth had a dad thing, he should have been worrying about her having a mom thing due to the early loss of her.

“He’s at least half, isn’t he.”

Byleth nods once more. “Full blooded.”

Fuck. No. Fuck.

“Where… where did you meet again?”

“I dug him out of the mausoleum under the school.”

Fucking fuck shit damn.

“So he’s how old?”

“Dunno, a thousand maybe.”

No. No. Fuck. No.

“Goddess, why?”

Byleth ends the conversation by saying, "I'm happy with him."

There's nothing Jeralt can say in response that wouldn't make him the biggest ass.

The worst part is, as they settle in for an awkward dinner, no matter how hard Jeralt tries to hate Seteth, he just can’t do it. He doesn’t even get the joy of giving a shovel talk because threatening a man who’s that much older than you would just be the worst. Everything about this is the worst.

Fuck.

**Notes for the Chapter:**

> The tags do not lie. Jeralt/Leonie is coming. If that squicks you, feel free to leave, my feelings won't be hurt. :P
> 
> What happens in this installment isn't important for the rest of the series.


	2. ...until you hook up with your daughter's student

Jeralt wakes up unusually refreshed. This is followed by immediate regret when he notices he’s gained a new bedmate with bright orange hair.

Ah, shit.

What the hell was she thinking? Leonie is much too young and talented to be wasting her time with old men. _And you, Jeralt,_ he scolds himself, _you should know better than to play accomplice to the self-destructive tendencies of youth!_

Oh yeah, it’s spring break and for the first year since she moved out, his daughter hasn’t rushed home to see him. She didn’t visit during winter break either. Because she’s engaged now, soon to marry a thousand-year-old dragon. Jeralt is a washed up, lonely, retired old man whose only joys in life are fishing and beating the shit out of youngsters in the boxing ring of the local gym under the guise of training them.

After the death of his wife, Jeralt spent plenty of years lost in his responsibilities. He busied himself with work and caring for Byleth so that he wouldn’t have to think about the what-ifs and could-have-beens. He didn’t look twice at another woman for a very long time. But eventually that pain dulled, as all things do. It was Byleth, as a teenager, who told him he looked lonely, so he mustered up the courage to start dating again, just casually. Most of the time it was just an excuse to have dinner with another lonely person.

He’s had a few girlfriends in more recent years, and yeah, some were a fair bit younger. None of them, however, had been young enough to be his daughter. That was always a line he swore he wouldn’t cross. Until now.

Jeralt takes a few deep breaths to calm himself, then gets up to make breakfast for himself and his guest. What’s done is done, and the least he can do now is offer a meal as part of his rejection and/or apology.

While the eggs and bacon are frying in the pan, he thinks over what he’ll say. “Go home and forget everything about last night!” Too harsh. “I can’t be what you need.” Too self-pitying. “We just aren’t meant to be.” Who the fuck would say something like that? It’s vague as all hell, and Jeralt will sound like a badly written romance novel over his dead body.

How do you break up with someone the morning after screwing them long and hard? That’s a question for the ages. The last time he had sex with a woman without establishing boundaries beforehand, he ended up marrying her. Hopefully Leonie will come to her senses on her own and say something like, “No offense, but you’re way old. I had fun, but let’s never do this again. I still look up to you as my boxing coach though! Having mindblowing sex with you (once and never again) can’t change how wholesome and pure our relationship is! I definitely never called you daddy in a sexual way, and if I did, you didn’t like it! Haha, wanna help me train for the MMA tournament next month?”

Yeah fucking right.

(She called him daddy and he liked it.)

Jeralt’s house is modest but has a large yard bordering the woodlands beyond where he can do some hunting and fishing. There are sliding glass doors in the kitchen that lead out this way, which he opens to let the spring breeze in. As he’s plating the last of the bacon, he hears soft footsteps and a yawn coming from behind. Leonie had helped herself to a quick shower. Her hair is still damp, and she’s wearing nothing but one of his ratty oversized t-shirts, leaving just about the entire length of her toned, athletic legs bare.

“Hey,” she says. “Morning.”

He nods. “Morning.”

“I almost thought you ditched me.” Leonie chuckles nervously as she takes a seat at the kitchen table, blush high on her cheeks, eyes lowered, fingers twirling a lock of hair that falls over her shoulder. “But then I remembered it was your house. And then I smelled the food.”

She glances up then, and Jeralt can’t help but think, _damn, what a woman_. Strong, but caring. Could kill a man with her thighs, and almost did just that to the disrespectful newbie who challenged her to a round in the ring last week. Yup, just his type. Why couldn’t she be a decade older?

Jeralt brings the plates over. He quietly sets them down. Leonie throws him a sweet smile before digging in, and it feels so nice and domestic, and he could _have_ all this… at the cost of his soul.

“Listen,” he says, “I’m… sorry about last night. It shouldn’t have happened.”

“What are you talking about?” she asks, strip of bacon still hanging from her mouth.

“We shouldn’t have done… what we did.”

Leonie pauses, goes silent, looks at him wide-eyed. She slowly sucks in the dangling piece of bacon, chews, swallows, and then there’s no response from her for a distressing amount of time.

“Ah… ah, geez, kid. I’m too poor to be a sugar daddy.”

 _That_ gets her attention. She immediately crosses her arms in a challenging manner. “S- _sugar daddy_? Are you trying to insult me until I go away? You know I’ve always worked hard for every scrap I have! I’ve always made my own way through life, and that’s never going to stop no matter who I’m with!”

He groans. “I know! I just can’t see any other reason you’d want to be with me. It’s not good for you! You should find a nice guy closer to your age.”

She’s angry now, venom dripping from her voice. “You know, most guys _your_ age would be over the _moon_ to have a hot younger girlfriend. Fucking _ecstatic_.”

“Well, maybe they don’t have a kid like I do. You raise up a daughter for two decades, you start thinking, ‘Shit, I don’t want some sleazy old man to take advantage of her,’ and then if you’re decent, you start thinking of all young ladies as some other guy’s daughters.”

She sucks in a breath, ready to give another sharp retort, then lets it out in a disappointed huff instead. “…You never mentioned having a kid.”

“Huh. Guess I don’t gush over her as much as I used to, now that she’s grown. Does that change anything for you?” he asks with a hint of hope, a bit of dread.

“Absolutely not. I’ve been in love with you for years. I know what I want.”

There it is, that terrifying complication he’s been dreading would come true. Jeralt has no idea what to say, where to go now that it’s out in the open. He wants to fall in love again, but…

“Ahem. Are you done now? Dad.”

He turns in the direction of the open door. Byleth is standing right there on the other side of the bug screen with an expression of mild concern on her face. She’s holding a fishing pole.

But oh no, that’s not the worst. Behind her is the dragon fiance, Seteth, also holding a fishing pole. And beside him? A teen girl, probably his daughter, holding the tackle box. The two of them look like they very much regret intruding.

His daughter came to see him. She didn’t forget about her old man after all, and she even brought hubby and the kid. They were all prepared to go fishing with grandpa, and here they’ve just walked in on this terrible soap opera scene. It _can’t_ get any worse than this.

“P-professor…”

“Ah, shit.”

* * *

Byleth has always liked Leonie. She’s one of her precious scholarship students, a hard worker who came from humble beginnings, tough and sensible and always looking out for the misfits of the Golden Deer. They have a lot in common, and perhaps could have been better friends if they weren’t separated by that line of professionalism between teacher and student.

Leonie dating her dad though?

NO.

NOPE.

DO NOT WANT.

Or at least that was her initial reaction. She invited Leonie to go fishing with them anyway.

Seteth looked like he wanted to oppose this relationship on moral grounds, but in the end he just leveled Leonie with his disapproving dad face and said, “I cannot dictate limits on who you may choose to consort with as a legal adult, Miss Pinelli, but do take care.”

Now all five of them are fishing in the woodland pond behind her dad’s house. He looks really constipated. Byleth supposes it’s not so surprising since from his perspective he gained a twenty year old girlfriend and a nine hundred year old granddaughter in the span of a few minutes.

They catch a good mix of perch, trout, and bass. The afternoon barbecue is delightful. They’ve avoided talking about the events of the morning for too long though, so after everyone is stuffed with fresh grilled fish, Byleth turns to Leonie and says, “I’ll never call you mom.”

“Fair enough,” Leonie replies. “I’d be freaked out if you did.”

Her dad hunches in on himself and starts to softly mumble ‘why’ over and over again. They might have broken him.

Eh. He’ll get over it.


End file.
